saac

1 hour ago, steppenwolf said:

Look like fudges to me too but then I’m just an ex-printer with a fancy camera 😂😂

I

Seeing an effect and hypothesising that there must be a cause is not a fudge it's the basis of all science. I'm still curious as to what it is that causes the trouble, is it the observation of the accelerated expansion and higher rotational speeds of the galaxies?  Is it these measurements that you are thinking as a "fudge".  Or is it the suggested causes - an energy and a form of matter?  In that case let's call them Thing A and Thing B  

I suppose the measurements could be incorrect but the Hubble Tension was confirmed by JWST not that long ago. It could of course be that there is an observational effect that we do not know of that introduces error. But for the meantime I think the two candidates are a reasoned response, in fact to not suggest them would be a dereliction or a fudge so to speak! 

Jim 

1 hour ago, vlaiv said:

Is that bowl of petunia thinking "Oh no, not again .... "?

Well spotted vlaiv, you got the reference  .

Jim

25 minutes ago, Paul M said:

That's my point, I think. You've given a good definition of "fudge" 😀

Certainly something is afoot, but maybe neither energy or matter in any sense we recognise. Will these "placeholders" be manifestations of one of the known forces or of something yet to be discovered

I just get the same GUT feeling about this as I did for String Theory, and (surely?) that's been put to bed now.

Don't all theories get replaced as further layers of reality reveal themselves?  String theory was no exception and it had its uses.  I guess as much as it may be frustrating, we only ever hold a momentary interpretation of reality.  Unlikely to be one of the fundamental forces given that we know how these interact.  A yet to be discovered force? Most definitely,  let's give them names, mmm how about  dark energy and dark matter, they seam appropriate given their apparent influence   That is all they are, placeholders for an observed nature, until we can further peel back the layers.

Jim  

35 minutes ago, Paul M said:

They just look so fudgy! It strikes me that they have been invoked to make the missing mass problem go away, but raise even more questions. Perhaps there is an upheaval in cosmology coming our way. I see occasional headlines that suggest cosmology is broken. Maybe it is?

My own theory is struggling to develop, don't bother watching this space 😁

I get where you are coming from but if it is a fudge then it is a fudge with reason behind it. Gravitational attraction would tend to collapse the universe while the expansion forces  would act in opposition. When we see an accelerated expansion it raises the question what is driving this. Dark Energy is then the place holder for whatever (unknown) is causing the acceleration in the expansion.  In a similar way dark matter is the place holder for whatever (unknown) is causing the observed higher rotational velocities of galaxies. So if they are fudges then they are fudges based on observational measurements and confirmed understanding of behaviour.  It would be exciting if the accelerated expansion and the excessive rotational speed of the galaxies turned out to be the result of something even more mysterious (if that were possible). If it does then there is potentially new physics to be discovered.   As for headlines - physics has always been in crisis since Newton fought Leibniz.  Everybody is competing for their share of funding. 

Jim 

5 hours ago, Stickey said:

Like I said, there's more than 1 type of infinity.

To see a World in a Grain of Sand
And a Heaven in a Wild Flower 
Hold Infinity in the palm of your hand 
And Eternity in an hour

William Blake - Auguries of Innocence 

While some are more poetic than others  

Jim 

They make available a free version for personal use. It has a few limitations over the paid for version - I think for example you are limited to store 10 working models at any one time as editable files. Easy enough to delete to free up space though. 

Jim

13 minutes ago, Elp said:

It really is easy, if you've ever done proper 3D modelling taking care of your topology lines, fusion is like child's play.

x 2 for Fusion - there's also plenty of support tutorials on YouTube. Another bonus is that Paul Gerlach (sgl member) has made available a Fusion 360 add-on for astro threads such as M42 etc - useful for extension tubes and adapters. 

Jim

4 minutes ago, iantaylor2uk said:

Complex behaviour generally occurs ultimately from very simple rules. There is a good paper from Turing on how patterns on animal skins (stripes, spots etc) occur due to very simple rules on chemical reactions when animals are young. There is also a good book on cellular automata by Wolf ram which explains how complex behavior can arise from very simple rules. 

I don't think we could argue that the universe is anything less than complex to our understanding Ian.  That the atom comprises a nucleus surrounded by an electron cloud appears non complex - the path to it's understanding was anything but simple. Similarly the equation to describe everything (when we arrive at it) will also appear simple because we will have understood it. 

Jim 

19 minutes ago, vlaiv said:

Here is an interesting question:

Is infinity purely mathematical construct or do we have something in nature that is infinite?

As far as I can see (there is a pun there somewhere I'm sure ) - everything that we've observed so far in this universe is finite.

Even some "philosophical" examples can be shown to be finite or rather depend on something that will be finite - take for example following argument:

Take a circle and marble and move marble on a circle - it can trace "infinite" length around the circle if it repeats itself. That would be physical infinity, right? Well - it implies that time needs to run to infinity and physical processes need to be undisturbed for duration of run - but we know that in expanding universe - that won't be the case. In fact, I don't think we need expanding universe - we just need second law of thermodynamics and fact that all will end in heat death to show that there is no infinite motion as described.

Which ever angle you adopt - you'll see that there simply is not infinity in physical world - so this begs a question - why would space be infinite?

Infinities in mathematics are sources of fun and frustration. Infinities in nature are just places waiting to be known   I believe the general consensus in physics is that infinities in nature do not exist in the common definition. 

Jim 

1 hour ago, Paul M said:

I feel think that too. 

But there have been numerous "dead-ends" along the way and the only thing that has increased along with our (their) knowledge is complexity. 

 Dark Matter and/or Dark Energy to be declared fudge factors or to be neither energy or matter. Waves, innit

I'll join you in doubling down Paul    Should we not expect greater complexity, if that is what we are finding then that is encouraging. 

As for dark matter/energy. Why do you think they are fudge factors?  In their absence what do you believe will explain the missing mass and what is causing the accelerated expansion and why would that be more credible than dark mater and dark energy?

Jim 

On 03/07/2024 at 12:09, Shimrod said:

I have just taken the plunge and ordered one of these while it is still on the reduced 'pre-order' price. I've chosen this one as it is small enough to pack into my camera bag and so can potentially travel with me abroad if I am going to somewhere with dark skies - I normally just take a small pair of binoculars.

I'm also interested in the potential for daytime use - both panoramas and bird tracking/photography. 

I've joined you Shimrod; waiting for September should be a nice little surprise just as the sky is getting darker. 

Jim 

Some amazing photographs of NLCs on the BBC News website.

https://www.bbc.co.uk/news/articles/cgl7rk9gjnmo

Jim 

1 hour ago, ollypenrice said:

 Because it's a sensible place for an astronomer to live! Lots of clear nights, minimal light pollution, a reasonable altitude, a minimum of 4 hours astronomical darkness in summer, no neighbours and 190 square metres of floor space for less than the price of a 2 up, 2 down terrace in Matlock. Plus a car every 20 minutes on local roads. I'd say it was perfect for your MGB but some of the hills are quite steep. 👹👹👹

lly

Oh she's definitely not a hill climber.

Jim

Absolutely beautiful. The fish eye shot is reminiscent of a photo of Earth from the ISS😀

Jim

They sell inflatable canoes, imagine that !

I look forward to the day that I can give up the car/ Not anti car far from it, I'm all for personal transport, but you get to a stage where you just can't be bothered with the hassle of it.  Mind you, I do like my little MGB, that's special  

I was in TISO the other day buying some new hill walking boots and the electric bikes caught my eye. Some were £9K plus - Crickey. Thinking about buying a canoe !

Jim 

17 hours ago, ollypenrice said:

You could just buy a house in a sensible place. Having spent the first fifty years of my life lashed to a rock in the north Atlantic I finally did so!

lly

Yea but how come you ended up in France Olly  🤪 

Jim 

Those images are trippy

Jim 

12 hours ago, Paul M said:

In my lifetime, and I'm 60 soon, no real progress has been made on the answer to this question. Yeah, lots of science and physics, lots of output, but no progress.

Indeed, it just got more complicated. 

 

I'm not sure I'd agree with that Paul, in fact I think the opposite is true. In the short jump from Hubble establishing that the universe was far larger than the originally envisaged confines of the Milky Way and Lemaitre's theory of the "Big Bang", to the phenomenal work of WMAP (2010) in providing the most detailed study of the CMBR which cemented the Standard Model (Lamda CDM) I'd say we have made pretty amazing insights to the nature of the universe.  I wouldn't be surprised if the nature of the universe is so complicated that it will remain beyond our ability to offer a full description but that does not detract from the profundity of our knowledge to date - all the more remarkable that it was acquired in such short order. In truth, I think every cosmologists worth their PhDs would hope for a never ending complexity. We don't want the mystery and fun to end  

Jim 

The catchy named COMPACT  (Collaboration for Observations Models and Predictions of Anomalies and Cosmological Topology) modeled a hyperdimensional doughnut (3 Torus) resulting in a line of sight in which endless images of the universe would unfold on itself like a hall of mirror effect. Usefully they concede that the shape of the universe remains entirely wide open.  One wonders if due to these bizarre "observational  effects" the true shape of the universe will forever be outwith our reach!

The Universe's Topology May Not Be Simple

Jim 

welcome to SGL @evmar. I think the jury is still undecided re state of the universe, really depends on its shape and mass/volume (critical density).  Here's some thoughts from somebody more knowledgeable than me. 

https://www.esa.int/Science_Exploration/Space_Science/Is_the_Universe_finite_or_infinite_An_interview_with_Joseph_Silk

Jim

26 minutes ago, GTom said:

Many thanks! I hope this will be rebranded by Altair too!  This one seems to be the most pro option.

In the meantime I think I'll just use my trusty laptop and familiarize with Nina...

 

Altair Cameras should certainly work with it. Who knows, in the long run it may prompt ZWO to open the AsiAir to non ZWO equipment. 

Jim 

You could also try the Toup Tek Astro Station but it is not available in UK yet so you may need to wait or try importing. It is a direct competitor to the AsiAir with the added bonus that it operates on a wide range of cameras. 

https://www.opticscentral.com.au/touptek-astro-station.html?ff=2&fp=5572

Jim 

On 02/07/2024 at 00:56, Ratlet said:

But how can you improve milk production from dairy cows if you don't understand spherical trigonometry?

https://en.wikipedia.org/wiki/Spherical_cow

Those spherical farmyard creatures have got me out of many a tight spot over the years. Almost as elusive as the mythical frictionless slope  

Jim 

Well done @Astro3dprintgeek very well executed. I love your description of the journey you went through in the design process. As a student (mechanical engineering) way back in the 1980s before the age of goto mounts, I wanted to build a control system for my telescope as part of my studies. I had neither the skills nor access to the wealth of information available to us now so sadly it didn't fly.  You may have just inspired me to revisit this and have a go at building my own now.  I notice from your youtube video you have made your work open source - congratulations and thanks for doing so this is very generous, well done.  I hope you are able to update us on how it continues to perform and what mods or upgrades you may make.  Oh an a big welcome to the forum, please stick around. 

Jim